Research progress of human bocavirus infection in children / 中华危重病急救医学

Human bocavirus is a novel pathogen first detected in respiratory tract samples in 2005. People of different ages can be infected by human bocavirus. Children are the susceptible population, especially the infants aged from 6-24 months old. The epidemic season varies in different regions due to the differences in climate and geographical location, and it mainly occurs in autumn and winter. It's demonstrated that human bocavirus-1 is closely related to respiratory system diseases and even causes life-threatening critical illness. Also, the severity of symptom is positively correlated with viral load. Co-infections between human bocavirus-1 and other viruses often present high frequency occurrence. Human bocavirus-1 interferes immune function of host by inhibiting interferon secrete pathway. Currently, it remains limited knowledge and understanding of the roles of human bocavirus 2-4 in diseases, but the gastrointestinal diseases should be paid more attention. Detection of human bocavirus DNA by traditional polymerase chain reaction (PCR) assay shouldn't be regarded as conclusive diagnostic basis. Instead, combined with mRNA and specific antigen detection, it is beneficial to improve the accuracy of diagnosis. Till now, the knowledge of human bocavirus remains poorly studied, which is deserved to further progress.

Description of a human Bocavirus recombinant strain in the Americas

Human bocaviruses (HBoV) are mainly associated with respiratory and gastroenteric infections. These viruses belong to the family Parvoviridae, genus Bocaparvovirus and are classified in four subtypes (HBoV1-4). Recombination and point mutation have been described as basis of parvovirus evolution. In this study three viral sequences were obtained from positives HBoV sewage samples collected in two Uruguayan cities and were characterised by different methods as recombinant strains. This recombination event was localised in the 5' end of VP1 gene and the parental strains belonged to subtypes 3 and 4. These three Uruguayan strains are identical at the nucleotide sequences in the analysed genome region of the virus. As far as we known, this study represents the first detection of HBoV recombinants strains in the Americas.

Establishment of stable cell line expressing human bocavirus type 1 non-structural protein NS1 and its trans-transcriptional activation / 生物工程学报

Human bocavirus 1 (HBoV1) non-structural protein NS1 is a multifunctional protein important for virus replication and induction of apoptosis in host cell. To better understand the function of the NS1 protein, it is urgent to address reducing the toxicity of NS1 to host cells. In the present study, we established a stable cell line that regulates expression of NS1 of HBoV1. The recombinant lentivirus plasmid containing a regulatable promoter fused with ns1 gene was constructed and transfected into HEK 293T cells using transfection reagent. The HEK 293T cell lines stably expressing NS1-100 and NS1-70 proteins were established by screening resistant cells with puromycin and inducing NS1 expression with doxycycline. The expression of NS1 protein was determined by fluorescent labeling protein and Western blotting. HBoV1 promoter was transfected into stably expressing NS1 cell line and its trans-transcriptional activity was analyzed. The results showed that NS1 protein was expressed stably in the established cell lines and had a strong activation activity on the HBoV1 promoter driving luciferase gene. Taken together, this study provides a solid basis for further research on the function of NS1 and the pathogenesis of human bocavirus.

Influence of Fine Particulate Dust Particulate Matter 10 on Respiratory Virus Infection in the Republic of Korea

BACKGROUND: This study investigated the effect of fine dust concentrations in the air on the incidence of viral respiratory infections in the Republic of Korea.METHODS: A time series analysis using R statistics was performed to determine the relationship between weekly concentrations of fine dust in the air and the incidences of acute respiratory tract infections caused by the respiratory syncytial virus (RSV), adenovirus (HAdV), rhinovirus (HRV), human metapneumovirus (HMPV), human coronavirus (HCoV), human bocavirus (HBoV), human parainfluenza virus (HPIV), and influenza virus (IFV), from the beginning of 2016 to the end of 2017. Correlations between various meteorological factors and the amount of fine dust were analyzed using the Spearman's rank correlation coefficient. To analyze the relationship between viral infections and fine dust, a quasi-poisson analysis was performed.RESULTS: The incidence of the HAdV was proportional to fine dust and air temperature. The IFV was proportional to fine dust and relative humidity and was inversely proportional to temperature. The HMPV was proportional to fine dust, wind speed, and inversely proportional to relative humidity. The HCoV was proportional to micro dust, relative humidity, and inversely proportional to temperature. Both the HBoV and HPIV were directly proportional to fine dust, temperature, wind speed, and inversely proportional to relative humidity. The RSV was inversely proportional to fine dust, temperature, wind speed. A lag effect was observed for the influenza virus, in that its incidence increased 2–3 weeks later on the cumulative lag model.CONCLUSION: As the weekly average concentration of fine dust increases, the incidence of HAdV, HMPV, HCoV, HBoV, HPIV, and influenza increase.

Human Bocavirus Infection in Adults: Clinical Features and Radiological Findings

OBJECTIVE: Human bocavirus (HBoV) is a newly identified pathogen that can cause upper and lower respiratory infections usually in children; however, its clinical characteristics and significance in respiratory infections in adults have not been well known. Our objective was to evaluate the clinical features of respiratory HBoV infection and to describe the CT findings of HBoV pneumonia in adults. MATERIALS AND METHODS: A total of 185 adult patients diagnosed with HBoV infection at a tertiary referral center between January 2010 and December 2017 were retrospectively evaluated with respect to the clinical characteristics of HBoV infection and its risk factors for pneumonia. Chest CT findings for 34 patients with HBoV pneumonia without co-infection were analyzed and compared between immunocompetent (n = 18) and immunocompromised (n = 16) patients. RESULTS: HBoV infections were predominantly noted between February and June. Among the 185 patients with HBoV infection, 119 (64.3%) had community-acquired infections and 110 (59.5%) had pneumonia. In multivariable analysis, older age (odds ratio [OR], 1.02; 95% confidence interval [CI], 1.00–1.04; p = 0.045) and nosocomial infection (OR, 2.07; 95% CI, 1.05–4.10; p = 0.037) were associated with HBoV pneumonia. The main CT findings were bilateral consolidation (70.6%) and/or ground-glass opacities (64.7%); centrilobular nodules (14.7%) were found less frequently. The pattern of CT findings were not significantly different between immunocompetent and immunocompromised patients (all, p > 0.05). CONCLUSION: HBoV infection can be a potential respiratory tract infection in adults. The most frequent CT findings of HBoV pneumonia were bilateral consolidation and/or ground-glass opacities.

Human metapneumovirus in Southern Brazil

INTRODUCTION Infections caused by respiratory viruses are important problems worldwide, especially in children. Human metapneumovirus (hMPV) is a respiratory pathogen and causes severe infections with nonspecific symptoms. This study reports the hMPV occurrence and dissemination in southern Brazil and compares the frequency of occurrence of this virus and the human respiratory syncytial virus (hRSV) in the epidemiological weeks in a three-year period (2009-2011). METHODS: In total, 545 nasopharyngeal (NP) specimens from individuals with Severe Acute Respiratory Syndrome (SARS) who were negative for other seven respiratory viruses were analyzed for the presence of hMPV. Human metapneumovirus was detected by direct immunofluorescence and real-time reverse transcription polymerase chain reaction. RESULTS: hMPV was detected in 109 patients from the main geographic regions of the southernmost state of Brazil, presenting similar overall prevalence in males (46.8%) and females (53.2%). Among children who were less than six years old, hMPV was detected in 99 samples of all age groups, with a higher frequency in infants who were less than one year old (45.7%) compared to all other age groups until six years. hMPV and hRSV infection occurred in almost the same epidemiological weeks (EWs) of each year, with peaks of incidence between EW 31/37 and EW 26/38 for the years 2009 and 2011, respectively. hMPV was further detected in several cases of SARS and it was the only virus detected in three deaths. CONCLUSIONS These findings indicate that hMPV is in circulation in southern Brazil and highlight the importance of diagnosing hMPV for influenza-like illness in the population. (AU)

Distribution and Characterization of Airborne Respiratory Pathogens in Public Facilities

Respiratory infections, which are caused by airborne pathogens, are the most common disease of all ages worldwide. This study was conducted to characterize the airborne respiratory pathogens in the public facilities in Busan, South Korea. A total of 260 public facilities were investigated in 2017, 52 seasonal indoor air from 2 hospitals and 208 indoor air samples from 208 randomly selected daycare centers. Among respiratory pathogen, 8 viral pathogens including human adenovirus (HAdV), human bocavirus (HBoV), human rhinovirus (HRV), human parainfluenza virus (HPIV), human respiratory syncytial virus (HRSV), human metapneumovirus (HMPV), human coronavirus (HCoV) and influenza virus (IFV), and 3 bacterial pathogens including Mycoplasma pneumoniae, Bordetella pertussis, and Chlamydophila pneumoniae, were investigated by multiplex real-time reverse transcription polymerase chain reaction. Pathogens were detected in 9 cases (3.4%). Among 9 positive samples, 6 (2.3%) cases were positive for HBoV and 3 (1.2%) cases were positive for IFV. All the positive cases were detected in daycare centers. Additionally, the concentration of HBoV was determined. In HBoV-positive samples, the cycle threshold (Ct) values of HBoV were 29.73~36.84, which are corresponding to the viral concentration of 4.91 × 10⁰ ~ 9.57 × 10² copies/ml. Serotype distribution of isolated HBoV was analyzed by sequencing of VP1/VP2 gene. All of the HBoV isolates were identified as HBoV type 1 with a high similarity among the isolates (>97%). No bacterial pathogen was identified in indoor air samples. Although virus concentration was not high in public facilities (daycare center), the presence of respiratory viral pathogens has been identified. Effective ventilation and air purification strategies are needed to reduce the indoor concentration of respiratory pathogens. A long-term and ongoing surveillance plan for respiratory pathogen management should be established.

Bronchiolitis severity according to the infected viruses

PURPOSE: The aim of this study was to evaluate the severity of disease in children with acute bronchiolitis according to the type of infected virus. METHODS: From November 2007 to May 2015, 768 patients under 2 years of age who underwent real time-polymerase chain reaction of nasopharyngeal aspirates admitted to the Department of Pediatrics of Dongguk University Ilsan Hospital for acute bronchiolitis were enrolled. Severe bronchiolitis was defined as presence of one or more kinds among tachypnea, chest retraction, needs of O2 inhalation or ventilator care. RESULTS: The severity of bronchiolitis was increased with shorter fever duration (P < 0.001) and previous wheezing episodes (P = 0.005). In the case of single infection, respiratory syncytial virus (RSV) A only increased the severity of acute bronchiolitis (P = 0.012). However, the severity of illness decreased when RSV A coinfected with adenovirus (P = 0.034), human rhinovirus (P = 0.038), or human coronavirus NL63 (P = 0.042). On the other hand, when human rhinovirus was coinfected with enterovirus (P = 0.013) or parainfluenza 3 (P = 0.019), the severity was increased. When human metapneumovirus coinfected with human bocavirus, the severity was increased (P = 0.038). CONCLUSION: Acute bronchiolitis was associated with increased severity only when RSV A infected solely, but several viruses increased or decreased the severity when coinfection occurred. Therefore, it may be helpful in predicting the course of the acute bronchiolitis according to the affected virus.

Three-dimensional Culture of Human Airway Epithelium in Matrigel for Evaluation of Human Rhinovirus C and Bocavirus Infections / 生物医学与环境科学（英文）

OBJECTIVE@#Newly identified human rhinovirus C (HRV-C) and human bocavirus (HBoV) cannot propagate in vitro in traditional cell culture models; thus obtaining knowledge about these viruses and developing related vaccines are difficult. Therefore, it is necessary to develop a novel platform for the propagation of these types of viruses.@*METHODS@#A platform for culturing human airway epithelia in a three-dimensional (3D) pattern using Matrigel as scaffold was developed. The features of 3D culture were identified by immunochemical staining and transmission electron microscopy. Nucleic acid levels of HRV-C and HBoV in 3D cells at designated time points were quantitated by real-time polymerase chain reaction (PCR). Levels of cytokines, whose secretion was induced by the viruses, were measured by ELISA.@*RESULTS@#Properties of bronchial-like tissues, such as the expression of biomarkers CK5, ZO-1, and PCK, and the development of cilium-like protuberances indicative of the human respiration tract, were observed in 3D-cultured human airway epithelial (HAE) cultures, but not in monolayer-cultured cells. Nucleic acid levels of HRV-C and HBoV and levels of virus-induced cytokines were also measured using the 3D culture system.@*CONCLUSION@#Our data provide a preliminary indication that the 3D culture model of primary epithelia using a Matrigel scaffold in vitro can be used to propagate HRV-C and HBoV.

Identification of Human Bocavirus type 4 in a child asymptomatic for respiratory tract infection and acute gastroenteritis - Goiânia, Goiás, Brazil

Abstract Human Bocavirus (HBoV) has been identified from feces and respiratory samples from cases of both acute gastroenteritis and respiratory illness as well as in asymptomatic individuals. The aim of this study was to detect and characterize HBoV from fecal samples collected from hospitalized children aged less than five years old with no symptoms of respiratory tract infection (RTI) or acute gastroenteritis (AGE). The study involved 119 children and one fecal sample was collected from each participant between 2014 and 2015. HBoV was detected using Nested-PCR, and the viral type identified by genomic sequencing. HBoV-4 was identified from one sample obtained from a hospitalized child with soft tissue tumor of the submandibular region. This is the first report of HBoV-4 identification in Brazil, but we consider that this type may be circulating in the country similar to the other types and new investigations are necessary.

Detecção e análise filogenética do bocavírus humano em crianças com infecção respiratória aguda no ano de 2010 em São Paulo, Brasil / Detection and phylogenetic analysis of human bocavirus in children with acute respiratory infection in the year 2010 in São Paulo, Brazil

O bocavírus humano (HBoV), gênero Bocavírus, família Parvoviridae está relacionado a doenças respiratórias, predominantemente na infância. Recebeu esta nomenclatura, devido a estrutura genômica apresentar similaridade aos gêneros parvovírus bovino e canino. Foram detectados 4 grupos: HBoV-1, HBoV-2, HBoV-3 e HBoV-4. Foi realizado um estudo retrospectivo, no ano de 2010, utilizando-se 300 amostras de secreção nasofaringe, coletadas de crianças de 0 a 5 anos de idade, com sintomas respiratórios agudo. As amostras foram registradas e processadas no Núcleo de Doenças Respiratórias do Instituto Adolfo Lutz. O objetivo foi detectar o vírus HboV e caracterizar filogeneticamente as cepas de HboV, nestas amostras e comparar com as sequencias depositadas no GenBank. Das 300 amostras analisadas através do teste de PCR em tempo real, 49 amostras (15,75%) foram positivas para HBoV. Todas estas amostras foram processadas por PCR, para a região do gene da VP1/VP2 do Bocavírus. Foram amplificadas 12 amostras e sequenciadas. As sequências de nucleotídeos obtidas em nosso estudo, foram comparadas com as sequências do Banco de gene e identificadas como do grupo HBoV 1. Os resultados mostraram que a ocorrência do HBoV é um fator importante, para a realização do diagnóstico diferencial que pode se manifestar associado, ou como visto neste estudo, como único agente causador da infecção. Este agravo é um fator que possibilita estabelecer medidas de controle para a vigilância epidemiológica, no auxilio clinico para a conduta no tratamento da doença. Estaremos introduzindo, no laboratório do Instituto Adolfo Lutz, a metodologia para identificação deste agente, para melhor atender à comunidade e a pesquisa científica. A caracterização molecular demonstrou ser do grupo HBoV1 que está circulando na da cidade de São Paulo o que poderá contribuir, para outros estudos na vigilância molecular desse vírus. (AU)

The human bocavírus (HBoV) genus Bocavírus Parvoviridae Family relates predominantly respiratory diseases in childhood. Received this nomenclature due to genomic structure present similarities to bovine and canine Parvovirus genres. Four groups were detected: HBoV-1, HBoV-2, HBoV-3 and HBoV-4. A retrospective study was carried out in the year 2010 using 300 nasopharyngeal secretion samples collected from children from 0 to 5 years of age with acute respiratory symptoms. The samples were recorded and processed in Respiratory Disease Center of the Adolfo Lutz Institute. Our goal was to detect the virus HboV and characterize HboV strains phylogenetically, in these samples and compare with the sequences deposited in GenBank. Of the 300 samples analysed by testing real-time PCR, 49 (15.75%) samples were positive for HBoV. All these samples were processed by PCR for gene region of VP1/VP2 of Bocavírus. 12 samples were amplified and sequenced. The nucleotide sequences obtained in our study were compared with the sequences of the gene Bank and identified as HBoV Group 1. The results showed that the occurrence of HBoV is an important factor for the differential diagnosis that can manifest associated or as seen in this study as single causative agent of infection. This interlocutory appeal is a factor that makes it possible to establish control measures for epidemiological surveillance in clinical assistance for conduct in the treatment of the disease. Clinical assistance in conduct for the treatment of the disease. We will be introducing in the Instituto Adolfo Lutz Laboratory methodology for identification of this agent to better serve the community and scientific research. The molecular characterization proved to be HBoV1 group that is circulating in the city of São Paulo which may contribute to other studies on molecular surveillance of this virus. (AU)

Comparison of etiology and clinical presentation between children with laryngotracheobronchopneumonitis and croup

PURPOSE: Croup, a common childhood respiratory illness with various severities, has many unanswered questions. Laryngotracheobronchopneumonitis (LTBP) is a disease entity considered to be an extension of croup to the lower respiratory tract. The object of this study was to compare epidemiology, clinical characteristics, and viral etiologic spectrum between croup and LTBP. METHODS: Patients hospitalized with croup at Gachon University Gil Hospital from January 2010 to April 2016 were recruited. LTBP was defined as pneumonia confirmed on radiographs of patients with croup. Clinical findings and demographic data were reviewed of patients whose nasopharyngeal swabs were done for viral analysis. RESULTS: A total of 371 patients with only croup and 63 patients with LTBP were included. Croup was found to be significantly associated with parainfluenza virus type 1 (P=0.006). LTBP was related to parainfluenza virus type 3, respiratory syncytial virus, and human bocavirus (P=0.001, P=0.030, and P=0.019, respectively). The duration of fever was longer in patients with LTBP than in those with croup (3.87±1.85 days vs. 2.86±1.80 days, P<0.001). CONCLUSION: Specific etiologic viruses might be associated with the progression from croup to LTBP. Pronged fever is also associated with progression from croup to LTBP.

Relationship between viral load of human bocavirus and clinical characteristics in children with acute lower respiratory tract infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the prevalence of human bocavirus (HBoV) in children with acute lower respiratory tract infection and to explore the relationship between the viral load of HBoV and the clinical characteristics of acute lower respiratory tract infection in children.</p><p><b>METHODS</b>A total of 1 554 nasopharyngeal aspirates from children who were hospitalized due to acute lower respiratory tract infection between March 2011 and March 2014 were collected. Quantitative real-time PCR was used to detect 12 RNA and 2 DNA viruses, adenovirus (ADV) and HBoV, and to measure the viral load of HBoV in HBoV-positive children. A comprehensive analysis was performed with reference to clinical symptoms and indicators.</p><p><b>RESULTS</b>In the 1 554 specimens, 1 212 (77.99%) were positive for viruses, and 275 (17.70%) were HBoV-positive. In HBoV-positive cases, 94.9% were aged <3 years, and there were more males than females. In the 275 HBoV-positive cases, 45 (16.36%) had single infection, and 230 (83.64%) had mixed infection. There was no significant difference in viral load between children with single infection and mixed infection (P>0.05). The patients with fever had a significantly higher viral load than those without fever (P<0.05). The children with wheezing had a significantly higher viral load than those without wheezing (P<0.05). There was no significant difference in viral load between children with mild, moderate, and severe acute lower respiratory tract infection (P>0.05).</p><p><b>CONCLUSIONS</b>HBoV is one of the important pathogens of acute lower respiratory tract infection in children. Children with a higher viral load of HBoV are more likely to experience symptoms such as fever and wheezing. However, the severity of disease and mixed infection are not significantly related to viral load.</p>

Prevalence of respiratory virus infection with regard to age, sex, and seasonality factors: A single center experience against children hospitalized during the 10 years

PURPOSE: It is well known that respiratory viral infection has epidemiological characteristics, including season. This study aimed to investigate the patterns of the prevalence of common respiratory viruses during a period of 10 years with regard to age, sex, and season in Korean children. METHODS: From June 2006 to November 2016, we obtained 11,798 specimens from patients aged less than 18 years who were admitted with lower respiratory infections. Ten respiratory viruses were detected using multiplex reverse transcription-polymerase chain reaction. RESULTS: Of 11,798 specimens, at least 1 virus was detected in 4,845 (41.1%). Respiratory syncytial virus (RSV, 18.9%) was the most common virus detected, followed by human rhinovirus (HRV, 14.8%), adenovirus (9.5%), and human bocavirus (HBoV, 7.4%). The detection rate of HRV was higher in male subjects (male 60.0% vs. female 40.0%, P=0.004), but the other viruses had no significant differences with regard to sex. The subjects who were positive for RSV test were youngest (median, 10.5 months; interquartile range, 3.0–25.0 months), followed by human coronavirus (median, 13.0 months), HRV (median, 14 months), and parainfluenza (median, 14 months). HBoV was most commonly detected in spring (29.3%), enterovirus in summer (25.8%), HRV in fall (22.6%), and RSV in October and winter (22.6%). CONCLUSION: We found that the prevalence of respiratory viruses in Korean children during a period of 10 years was associated with age, sex, and season when the infection occurred. Further nationwide data is warranted to infer clinical implication of our results.

Bocavirus en niños menores de 5 años con infección respiratoria aguda: Provincia del Chaco, 2014 / Bocavirus in infants under 5 years with acute respiratory infection. Chaco Province, Argentina, 2014

La infección respiratoria aguda (IRA) es la patología más frecuente a lo largo de la vida de una persona y es la causa más común de morbi-motalidad en menores de 5 años. El objetivo de este trabajo fue determinar la frecuencia de bocavirus (BoV) en pacientes menores de 5 años con diagnóstico presuntivo de IRA en una ciudad capital del norte argentino (Resistencia, Chaco). Se analizaron aspirados nasofaríngeos correspondientes a 488 niños durante el año 2014. Los mismos fueron testeados por PCR en tiempo real hallándose BoV en 36 casos (7.4%), de los cuales 26 (72.2%) fueron infantes de 6-18 meses de vida. La mayor concentración de positivos se registró en el período junio-septiembre con un total de 28 pacientes (77.8%). Los casos positivos para BoV se observaron como infección única en el 50% de los mismos y el resto como infecciones concomitantes con otros microorganismos. No conocemos que haya otro estudio de epidemiología molecular de BoV en el norte argentino y destacamos la importancia de investigar los nuevos virus capaces de generar infección respiratoria aguda, y difundir el conocimiento de su circulación en la comunidad.

Acute respiratory infection (ARI) is the most frequent pathology along human life, being the most common cause of morbidity and mortality in children under 5 years. The aim of this study was to determine the frequency of bocavirus (BoV) in infants under 5 years with symptoms of ARI from north Argentina (Chaco province). The study was performed on nasopharyngeal aspirates from 488 patients, in the period of January-December 2014. The samples were tested by real time PCR and 36 positive BoV cases (7.4%) were detected. The period with the highest detection rate was June-September with 28 cases (77.8%), of which 26 (72.2%) were infants between 6-18 moths of life. In half of BoV positive cases this virus was detected as single infection of the upper respiratory tract, and in the remaining 50%, as concomitant infection with other microorganisms. To our knowledge, this would be the first study on molecular epidemiology of BoV in northern Argentina. We emphasize the importance of investigating these new viruses capable of generating acute respiratory disease and also to disseminate awareness on their circulation within the community.

Detección de bocavirus humano en la población infantil de Tucumán y Santa Fe, Argentina / Detection of human bocavirus in children from Tucuman and Santa Fe, Argentina

Background: A large proportion of acute respiratory tract infections (ARTI) remain without etiologic diagnosis, reason why new pathogens are investigated continuously. Human bocavirus (HBoV) was discovered in 2005, as a new member of Parvoviridae family and proposed to cause ARTI. Aim: To know the prevalence of HBoV among pediatric populations hospitalized for ARTI in two provinces of Argentina: Santa Fe and Tucuman; and to describe epidemiological and clinical aspects associated to its detection. Materials and Methods: We studied nasopharyn-geal aspirates of patients younger than 5 years old that were hospitalized during 2013 due ARTI. HBoV DNA was assayed using PCR described by Allander et al. Traditional virnses were studied by immunofluorescence. Personal, clinical and epidemiological data were collected in a standardized form. Results: The HBoV was detected in 7% of the samples and was prevalent in spring and summer and in children younger of 2 years old. Other respiratory viruses were detected in 22% of HBoV positive samples. Discussion: We detected HBoV in these two provinces of Argentina. Further studies should be performed to determine if it’s a recent infection or prolonged viral shedding.

Introducción: Un alto porcentaje de las infecciones respiratorias agudas (IRA) permanece sin diagnostico etiológico, por lo cual se investigan nuevos patógenos continuamente. Bocavirus humano (HBoV) fue descubierto en 2005, como un nuevo miembro de la familia Parvoviridae y propuesto como causante de IRA. Objetivos: Investigar la prevalencia de HBoV en niños bajo 5 años de edad, hospitalizados por IRA en dos provincias de Argentina: Santa Fe y Tucumán y describir aspectos epidemiológicos y clínicos asociados a su detección. Materiales y Métodos: Se estudiaron retrospectivamente los aspirados nasofaríngeos (ANF) de pacientes bajo 5 años de edad, con diagnóstico de IRA, hospitalizados durante el año 2013. La presencia de HBoV se detectó mediante la RPC de punto final descripta por Allander y cols. Los virus tradicionales se estudiaron mediante inmunofluorescencia. Datos personales, clínicos y epidemiológicos se recolectaron en una planilla estandarizada. Resultados: HBoV fue detectado en 7% de las muestras con prevalencia en primavera y verano; y principalmente en pacientes bajo 2 años de edad. Se registró co-detecciones en 22% de los casos. Discusión: Hemos detectado HBoV en estas dos provincias de Argentina; estudios posteriores deberán efectuarse para determinar si se trata de una infección reciente o una excreción prolongada del virus.

Circulación de Bocavirusen niños menores de 5 años con infección respiratoria aguda de la provincia del Chaco: análisis de los años 2014 y 2015 / Bocavirus circulation in children under 5 years with acute respiratory infection in the province of Chaco: analysis of 2014 and 2015

Acute respiratory infection (ARI) is the most frequent pathology along human life, being the most common cause of morbidity and mortality in children under 5 years old. The aim of this study was to determine the circulation of HBoV in infants under 5 years old with symptoms of ARI from north Argentina (Chaco province). Were analyzed 882 nasopharyngeal aspirates obtained during the years 2014 and 2015. The samples were tested by real time PCR and the overal frequency of HBoV was 7.6%. The period with the major detection report was June-September with 77.6% of all positive cases. It is interesting that 98.5% of all cases were in infants aged 0 to 2 years of life. HBoV positive cases were given as single infection in 46.3% of patients and the remaining 53.7% as concomitant infections with other viruses. The evaluation of two full years calendar of molecular epidemiological study in northern Argentina of HBoV, reflects more accurately the current situation and could lead to re-formulate strategies for diagnosis, treatment and prognosis of this disease. We intend to highlight the importance of investigate this new virus capable of produce an acute respiratory disease by providing information about it to the community.

A infecção respiratória aguda (IRA) é a mais frequente ao longo da vida de uma patologia individual e é a causa mais comum de mortalidade/morbidade em crianças com menos de 5 anos. O objetivo deste estudo foi determinar o movimento do Bocavírus Humano (HBoV) em crianças menores de 5 anos com um diagnóstico presuntivo de IRA numa capital estadual do norte da Argentina (Resistencia, Chaco). Foram analizados 882 aspirados nasofaríngeos, obtidos durante os anos 2014 e 2015. As pessoas foram testeadas por PCR em tempo real, onde se encontrou uma frequência de HBoV do 7,6% (67/882), dando a maior concentração de casos positivos no período de junho a setembro (77,6%). Curiosamente, 98,5% dos casos foram em crianças de 0 a 2 anos de vida. Os casos positívos de HBoV foram dados como única infecção em 46,3% dos pacientes e os restantes 53,7% como infecções concomitantes com outros vírus. A avaliação de dois anos, calendário completo de estudo de epidemiologia molecular HBoV no norte da Argentina, reflete com mais precisão a realidade, e pode reformular as estratégias para o diagnóstico, tratamento e prognóstico da patología. Temos a intenção de destacar a importância de se investigar o novo vírus capaz de gerar doença respiratória aguda, fornecendo informações dele para a comunidade

La infección respiratoria aguda (IRA) es la patología más frecuente a lo largo de la vida de una persona y es la causa más común de morbi-motalidad en niños menores de 5 años. El objetivo de este trabajo fue determinar la circulación del Bocavirus Humano (HBoV) en niños menores de 5 años con diagnóstico presuntivo de IRA en una ciudad capital del norte argentino (Resistencia, Chaco). Ruiz Díaz, Natalia; y Col. Rev. Fac. Med. UNNE XXXVI: 3, 5-12, 2016 Se analizaron 882 aspirados nasofaríngeos obtenidos durante los años 2014 y 2015. Los mismos fueron testeados por PCR en tiempo real encontrándose una frecuencia de HBoV de 7.6% (67/882), dándose la mayor concentración de casos positivos en el período junio-septiembre (77,6%) y es interesante destacar que el 98,5% del total de casos se registraron en infantes entre 0 a 2 año de vida. Los casos positivos para HBoV se dieron como infección única en el 46.3% de los pacientes y el 53.7% restante como infecciones concomitantes con otros virus. La evaluación de dos años -calendarios completos- de estudio epidemiológico molecular de HBoV en el norte argentino, refleja de manera más fiel la realidad ya que permite reformular las estrategias en cuanto al diagnóstico, el tratamiento y el pronóstico de esta patología. Pretendemos destacar la importancia de investigar los nuevos virus capaces de generar patología respiratoria aguda brindando información sobre el mismo a la comunidad

prevalence of human Bocavirus, human Coronavirus-NL63, human Metapneumovirus, human Polyomavirus KI and WU in respiratory tract infections in Kuwait

Objective: The aim of this study was to investigate the prevalence of human coronavirus [HCoV]-NL63, human metapneumovirus [hMPV], human bocavirus [Boca], human polyomavirus KI [KIV] and human polyomavirus WU [WUV] in respiratory tract infections [RTI] in Kuwait

Materials and Methods: Respiratory samples from 735 hospitalized patients with RTI from September 2010 to April 2013 were evaluated for the presence of HCoV-NL63, hMPV, Boca, KIV and WUV using molecular assays, polymerase chain reaction [PCR] and reverse-transcription PCR

Results: Of the 735 patients, 285 [38.8%] were diagnosed with viral RTI. The distribution of respiratory viruses was hMPV: 15 [5.3%], Boca: 14 [4.9%], WUV: 10 [3.5%] and KIV: 4 [1.4%]. HCoV-NL63 was not detected in any of the samples

Conclusions: These newly discovered viruses were associated with the development of RTI in Kuwait. The rapid identification of these viral infections could aid in the control of nosocomial transmission, reduce the use of antibiotics and improve treatment and management strategies

Discovery of human bocavirus 4 in children with acute gastroenteritis in Lanzhou, China / 病毒学报

We studied the epidemiological characteristics of human bocavirus 4 (HBoV4) in children with a- cute gastroenteritis in Lanzhou (China). A total of 331 stool specimens were collected from children aged < 5 years with acute diarrhea at the First Hospital of Lanzhou University between July 2012 and June 2013. Specimens of HBoV were identified by nested polymerase chain reaction assays. Compared with related sequences in GenBank, the HBoV-positive strain isolated in the present study was,quite surprisingly, a rare genotype named HBoV4. This strain was a typical HBoV4,with high levels of nucleotide and amino acid homology to the Thailand strain, JQ267789 (98.9% and 98.7%, respectively), and the USA strain, GQ506568 (97.6% and 97.4%, respectively). This is the first report of HBoV4 as the causative agent for acute gastroenteritis in pediatric patients in China. This strain is one of two genotypes of HBoV that are currently circulating.

Clinical characteristics of respiratory viral infection in children during spring/summer: focus on human bocavirus

PURPOSE: We evaluated the clinical characteristics of respiratory viruses that were frequently found in children during spring/summer, namely, human bocavirus (hBoV), human metapneumovirus (hMPV), parainfluenza virus (PIV), and human rhinovirus (hRV). METHODS: This study enrolled patients with acute lower respiratory infection in whom respiratory virus reverse transcriptase polymerase chain reaction was performed between March 2013 and August of 2013. We retrospectively reviewed the medical records to collect the patients' data. RESULTS: A total of 96 patients were enrolled and divided into 5 categories: hBoV in 19 patients (19.8%), hMPV in 18 patients (18.8%), PIV in 16 patients (16.7%), hRV in 20 patients (20.8%), and negative result in 23 patients (24.0%). The mean age of the patients was 8.2+/-5.9 months (median, 7.5 months; range, 1-24 months), and the male-to-female ratio was 1.1:1. The most common diagnoses were acute bronchiolitis (62.5%) and pneumonia (30.2%). Compared to other patients, those with hBoV were older (12.3+/-4.9 months, P=0.001) and more frequently diagnosed with acute bronchiolitis (P=0.005). In addition, they showed higher incidences of tachypnea and rales (P=0.039 and P=0.035, respectively), and were more frequently treated with oxygen and systemic steroids (P=0.044 and P=0.001, respectively) than the other patients. CONCLUSION: We compared respiratory viruses in children during spring/summer and found that hBoV may have more severe clinical manifestations than other viruses.